A method of supplying electrical appliances of a vehicle

ABSTRACT

Disclosed is a method for control of a vehicle with a drive system comprising an output shaft in a combustion engine and a planetary gear with a first and a second electrical machine connected via their rotors to the components in the planetary gear, a supply of electrical power to electrical auxiliary units and/or loads present in the vehicle is carried out, by way of the combustion engine being kept running with its output shaft connected with the second electrical machine&#39;s rotor, and the electrical auxiliary units and/or loads being supplied with electrical power via the first electrical machine and/or the second electrical machine.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a national stage application (filed under 35 §U.S.C. 371) of PCT/SE2014/051570, filed Dec. 23, 2014 of the same title,which, in turn, claims priority to Swedish Application No. 1351574-7,filed Dec. 23, 2013; the contents of each of which are herebyincorporated by reference.

FIELD OF THE INVENTION

The present invention relates to a method for the control of a vehicle,and is particularly, but not exclusively, focused on the performance ofsuch a method in motor vehicles in the form of wheeled commercialvehicles, especially heavy goods vehicles, such as trucks and buses. Theinvention thus relates to a method carried out in a hybrid vehicle,which, generally, is a vehicle that may be powered by a primary engine,e.g. a combustion engine, and a secondary engine, such as at least oneelectrical machine. The vehicle is suitably, but for the purposes of thepresent invention not necessarily, equipped with means for storage ofelectric energy, such as a battery or a capacitor for storage ofelectric energy, and control equipment to control the flow of electricenergy between the means and the electrical machine. The electricalmachine(s) may in such a case alternately operate as an engine or as agenerator, depending on the vehicle's operating mode. When the vehicledecelerates, the electrical machine generates energy that may be stored,and the stored electric energy is used later for e.g. operation of thevehicle.

BACKGROUND OF THE INVENTION

Using a conventional clutch mechanism which disconnects the gearbox'sinput shaft from the combustion engine during a shifting process in thegearbox entails disadvantages, such as heating of the clutch mechanism'sdiscs, which results in an increased fuel consumption and wear of theclutch discs. There are also large losses as a result, in particularwhen the vehicle is started. A conventional clutch mechanism is alsorelatively heavy and costly. It also occupies a relatively large spacein the vehicle. Friction losses also arise at the use of a hydraulicconverter/torque converter commonly used in automatic transmission. Byensuring that the vehicle has a drive system in which the output shaftof the combustion engine, the rotor of the electrical machine and theinput shaft of the gearbox are connected with a planetary gear, theconventional clutch mechanism and the disadvantages associated therewithmay be avoided. A vehicle with a drive system of this type constitutesprior art as set out in EP 1 319 546 and SE 536 329.

Certainly, a range of advantageous methods to control a vehicle with adrive system of the type described in SE 536 329 constitute prior art,however there is naturally a constant endeavor to improve the manner ofcontrolling such vehicles, especially in certain specific operatingsituations.

SUMMARY OF THE INVENTION

The objective of the present invention is to show a method of the typedefined above, which is in line with the above-mentioned endeavor. Thisobjective is achieved according to the invention by providing a methodfor control of a vehicle with a drive system.

Having a drive system in a vehicle with a second electrical machineopens up a possibility for an improved behavior in a range ofoperational situations compared to prior art drive systems lacking sucha design of the drive system. Such a constantly occurring operationalsituation in a vehicle of this type consists of supplying a vehicle'selectrical auxiliary units and/or loads with electrical power, andachieving this in accordance with the invention, by way of continuousrunning of the combustion engine with its output shaft connected to thesecond electrical machine's rotor, and supplying the electricalauxiliary units and/or loads with electric power via the firstelectrical machine and/or the second electrical machine. The steps a)and b) are thus carried out in parallel, and by connecting thecombustion engine a continuous supply of the electrical auxiliary unitsand loads may thus take place in all operating modes. This is normallynot achieved with hybrid solutions having only one electrical machine.

According to one embodiment of the invention, the method is implementedwith the first locking means in its locked position, and in step b) saidelectrical auxiliary units and/or loads are supplied with electricalpower requested thereby and distributed between the first and the secondelectrical machine, in such proportions that the total power loss isminimized. Such loss minimization is naturally advantageous, andaccording to another embodiment of the invention the method isimplemented with the first locking means in its locked position, andinstep b) said electrical auxiliary units and/or loads are supplied withelectrical power requested thereby, in substantially equal parts fromthe first and the second electrical machines. This is advantageous froma loss minimization perspective, since the torque per electrical machineis halved compared to if one electrical machine supplies all of theelectrical power, and since the electrical machines' loss effectssubstantially scale toward the torque applied squared, this entails thatlosses in the electrical machines are halved. However, such adistribution (50/50) is potentially not optimal in case the twoelectrical machines have dimensions which differ considerably from eachother, but efforts are still made to select said proportions with thisoptimal distribution in mind.

According to another embodiment of the invention the method isimplemented with said first locking means in its release position, andthe method also comprises the following steps:

-   c) engine speed control of the combustion engine to an operational    point, which is selected by minimizing combustion engine losses    together with losses in the electrical machines and losses in    inverters, comprised in the vehicle's electrical systems for    conversion of direct voltage to alternating voltage and vice versa,-   d) control of the second electrical machine for balancing of the    electrical power transmitted to said electrical auxiliary units    and/or loads and the first electrical machine, and-   e) control of the first electrical machine to achieve, throughout    the progress of the entire method, a requested torque for    transmission to said output shaft of the planetary gear, wherein    steps c), d) and e) are carried out substantially in parallel.    Naturally, the steps a) and b) are also carried out in parallel with    these steps.

According to another embodiment of the invention a vehicle iscontrolled, which has a drive system that also comprises a secondlocking means that may be moved between a locked position in which thecombustion engine's output shaft is locked together with the secondelectrical machine's rotor and said first component, and a releaseposition in which the combustion engine's output shaft is disconnectedfrom the second electrical machine's rotor and said first component isallowed to rotate independently of these, the second locking means beingin said locked position at the performance of the method. Such secondlocking means facilitates the disconnection of the combustion enginefrom the planetary gear, when the vehicle is powered purelyelectrically.

According to another embodiment of the invention a vehicle iscontrolled, whose drive system also comprises at least one electricenergy storage means, for exchange of electric power with the first andsecond electrical machine and said electrical auxiliary units and/orloads.

“Electrical energy storage means” as used in this document means anenergy storage means with an electrical interface in relation to thefirst and second electrical machine of the drive system, but storage ofenergy does not have to be electrical. This entails that in addition toan electrical battery and capacitor, for example flywheels, othermechanical means and means for building up pressure, e.g. pneumatic orhydraulic means, may be considered.

According to another embodiment of the invention, supply of saidelectrical auxiliary units and/or loads is carried out with electricalpower, so that power balance is achieved, wherein free selection, withinthe limitations generally specified for the drive system, of chargecurrent to, or discharge current from electric energy storage means,and/or electric auxiliary units and/or loads occurs that may be presentin the vehicle, in accordance with the prevailing operational situationin the vehicle.

According to another embodiment of the invention, where needed, themaintenance of power balance is temporarily waived while said supply isimplemented.

According to another embodiment of the invention, the method is carriedout in a vehicle with a said drive system, in which the planetary gear'ssun wheel is said first component and the ring gear is said thirdcomponent. By connecting the first electrical machine's rotor with thering gear and the combustion engine's output shaft with the sun wheel acompact construction is achieved which is easy to fit into alreadyexisting spaces for powertrains (drive systems) with clutch mechanismsinstead of planetary gears.

According to another embodiment of the invention the method isimplemented in a vehicle with a gearbox having an input shaft, which isconnected with said second output shaft in the planetary gear. Via theinventive method, the combustion engine may be started without anytorque interruption, and with a potential for the driver of the vehicleto maintain or change the torque transmitted to the vehicle'spowertrain.

The invention also relates to a computer program product, and anelectronic control device.

Other advantageous features and advantages with the invention are setout in the description below.

BRIEF DESCRIPTION OF THE DRAWINGS

Below are descriptions of an example embodiment of the invention withreference to the enclosed drawings, in which:

FIG. 1 is a very simplified view of a powertrain in a vehicle that maybe equipped with a drive system for the performance of a methodaccording to the invention,

FIG. 2 is a more detailed, but still simplified view of a part of saiddrive system,

FIG. 3 is a simplified view, illustrating the general structure of adrive system in a vehicle, for which a method according to oneembodiment of the invention is carried out,

FIG. 4 is a simplified view, illustrating the general structure ofanother drive system in a vehicle, for which a method according to oneembodiment of the invention is carried out,

FIG. 5 is a flow chart showing a method according to one embodiment ofthe invention, and

FIG. 6 is a fundamental diagram of an electronic control device forimplementation of one or several methods according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a powertrain for a heavy goods vehicle 1. The powertraincomprises a combustion engine 2, a power transmission 3 in the form offor example a speed gearbox, a continuously variable transmission (CVT),or a direct transmission, a number of driving shafts 4 and drivingwheels 5. Between the combustion engine 2 and the gearbox 3 thepowertrain comprises an intermediate section 6. FIG. 2 shows a part ofthe components in the intermediate section 6 in more detail, morespecifically those which also occur in prior art drive systems, such asthe one according to SE 536 329. The combustion engine 2 is equippedwith an output shaft 2 a and the gearbox 3 with an input shaft 3 a inthe intermediate section 6. The output shaft 2 a of the combustionengine is coaxially arranged in relation to the input shaft 3 a of thegearbox. The combustion engine's output shaft 2 a and the input shaft 3a of the gearbox are rotatably arranged around a common rotation axis 7.The intermediate section 6 comprises a house 8, enclosing a firstelectrical machine 9 and a planetary gear. The electrical machine 9comprises, in a customary manner, a stator 9 a and a rotor 9 b. Thestator 9 a comprises a stator-core which is fixed in a suitable manneron the inside of the house 8. The stator core comprises the stator'swindings. The first electrical machine 9 is adapted, under certainoperating circumstances, to use stored electrical energy to supplydriving force to the input shaft 3 a of the gearbox and under otheroperating conditions, to use the kinetic energy of the input shaft 3 ofthe gearbox to extract and store electric energy.

The planetary gear is arranged substantially radially inside of theelectrical machine's stator 9 a and rotor 9 b. The planetary gearcomprises, in a customary manner, a sun wheel 10, a ring gear 11 and aplanetary wheel carrier 12. The planetary wheel carrier 12 supports anumber of cogwheels 13 which are rotatably arranged in a radial spacebetween the teeth of the sun wheel 10 and the ring gear 11. The sunwheel 10 is fixed on a peripheral surface of the combustion engine'soutput shaft 2 a. The sun wheel 10 and the combustion engine's outputshaft 2 a rotate as one unit with a first rotational speed n₁. Theplanetary wheel carrier 12 comprises an attachment section 12 a which isattached on a peripheral surface of the input shaft 3 a of the gearboxwith the help of a splines-joint 14. With the help of this joint, theplanetary wheel carrier 12 and the gearbox's input shaft 3 a may rotateas one unit with a second rotational speed n₂. The ring gear 11comprises an external peripheral surface on which the rotor 9 b isfixedly mounted. The rotor 9 b and the ring gear 11 constitute onerotatable unit which rotates at a third rotational speed n₃.

The drive system comprises a first locking means since the combustionengine's output shaft 2 a is equipped with a shiftable clutch element15. The clutch element 15 is mounted on the combustion engine's outputshaft 2 a with the help of a splines-joint 16. The clutch element 15 isin this case arranged in a twist-fast manner on the combustion engine'soutput shaft 2 a, and is shiftably arranged in an axial direction on thecombustion engine's output shaft 2 a. The clutch element 15 comprises aclutch section 15 a, which is connectible with a clutch section 12 b inthe planetary wheel carrier 12. A schematically displayed shiftingelement 17 is adapted to shift the clutch element 15 between a firstposition where the clutch sections 15 a, 12 b are not in engagement witheach other, corresponding to a release position in the first lockingmeans, and a second position where the clutch sections 15 a, 12 b are inengagement with each other, corresponding to a locked position of thefirst locking means. In such locked position the combustion engine'soutput shaft 2 a and the gearbox's input shaft 3 a will be lockedtogether and accordingly these and the electrical machine's rotor willrotate at the same engine speed. This state may be referred to as alocked planet. The locking mechanism may also advantageously have thedesign described in the Swedish patent application SE 536 559, andcomprise a sleeve equipped with first splines, which engage, in therelease position, with second splines on a first component of theplanetary gear, and in the locked position, engage with third splines ona second component of the planetary gear. In this case the firstcomponent is preferably the planetary wheel carrier and the secondcomponent is the sun wheel. The locking mechanism may then be adaptedlike an annular sleeve, enclosing the planetary wheel carriersubstantially concentrically. The locking means may also be made of asuitable type of friction clutch.

An electronic control device 18 is adapted to control the shiftingelement 17. The control device 18 is also adapted to determine theoccasions on which the electrical machine should operate as an engineand the occasions on which it should operate as a generator. In order toso determine, the control device 18 may receive up to date informationrelating to suitable operating parameters. The control device 18 may bea computer with software for this purpose. The control device 18controls a schematically displayed control equipment 19, which controlsthe flow of electric energy between a hybrid battery 20 and the statorwindings 9 a of the electrical machine. On occasions where theelectrical machine 9 operates as an engine, stored electric energy issupplied from the hybrid battery 20 to the stator 9 a. On occasionswhere the electrical machine operates as a generator electric energy issupplied from the stator 9 a to the hybrid battery 20. The hybridbattery 20 delivers and stores electric energy with a voltage in therange of 300-900 Volt. Since the intermediate section 6 between thecombustion engine 2 and the gearbox 3 in the vehicle is limited, theelectrical machine 9 and the planetary gear must constitute a compactunit. The planetary gear's components 10, 11, 12 are arrangedsubstantially radially inside the electrical machine's stator 9 a. Therotor 9 b of the electrical machine, the ring gear 11 of the planetarygear, the combustion engine's output shaft 2 a and the input shaft 3 aof the gearbox are here rotatably arranged around a common rotation axis5. With such an embodiment the electrical machine 9 and the planetarygear occupy a relatively small area. The vehicle 1 is equipped with anengine control function 21 with which engine speed n₁ and/or torque ofthe combustion engine 2 may be controlled. The control device 18accordingly has the possibility of activating the engine controlfunction 21 and of creating a substantially zero torque state in thegearbox 3 at engagement and disengagement of gears in the gearbox 3.Naturally, the drive system may, instead of being controlled by onesingle control device 18, be controlled by several different controldevices.

The part of a drive system of a vehicle, thus far described, anddisplayed at FIG. 2, on which a method according to the invention may beimplemented is extant in the drive system according to SE 536 329.Below, a part of the drive system, which may be added to this part forthe performance of the invention, will be described with reference toFIG. 3.

The drive system, specifically the intermediate section 6, also has asecond electrical machine 30 with a stator 31, with stator windings anda rotor 32 which is connected with the combustion engine's output shaft2 a. A second locking means 33, which may have a similar design as thefirst locking means 34, illustrated in more detail in FIG. 2, is adaptedto separate, in a release position, a first part 35 of the combustionengine's output shaft, arranged nearest the combustion engine, from asecond part 36 thereof connected with the sun wheel 10 of the planetarygear, so that the second electrical machine's rotor 32 and the sun wheel10 are allowed to rotate independently of the first section 35 of thecombustion engine's output shaft. The second locking means may be movedto a locked position in which both the parts 35, 36 of the combustionengine's output shaft are locked together, and accordingly the firstpart 35 is locked together with the second electrical machine's rotor.The control device 18 is adapted to control fuel supply to thecombustion engine 2 and to control exchange of electric energy betweenthe first electrical machine 9 on the one hand, and the secondelectrical machine 30, and, on the other hand, electric energy storagedevices such as batteries and electric auxiliary units and loads in thevehicle, such as servo control units, pumps, cooling aggregates andsimilar.

A range of positive features are achieved in the drive system throughthe added arrangement of the electrical machine 30 and the secondlocking means 33. If the vehicle is driven with the first locking means34 in a locked position and for example the second locking means 33 in alocked position, and a request arises for shifting the first lockingmeans 34 into a release position, the power unit configuration iscontrolled towards a torque balance between the components that arelocked together, i.e. the planetary wheel carrier 12 and the sun wheel10, via the first locking means 34. This may be achieved by controllingthe first electrical machine 9 and at least one of the second electricalmachine 30 and the combustion engine 2, since the second locking means33 is in a locked position, towards said torque balance, so that thereis also a possibility for energy storage in the hybrid battery 30 ifdesired. Here, torque balance is achieved when the following relationbetween the torques applied is met for the example configurationdisplayed in FIG. 3:

$T_{{sun}\mspace{14mu} {wheel}} = {\frac{Z_{s}}{Z_{r}}T_{{ring}\mspace{14mu} {gear}}}$

where

-   T_(sun wheel) and T_(ring gear) represent the torque applied to the    sun wheel and the ring gear, respectively, where    T_(sun wheel)=T_(ice)+T_(em2) and T_(ring gear)=T_(em1) where-   T_(ice) is torque applied to the combustion engine's output shaft-   T_(em2) is torque applied via the second electrical machine's stator    to its rotor-   T_(em1) is torque applied via the first electrical machine's stator    to its rotor,-   Z_(s) is the number of teeth on the sun wheel,-   Z_(r) is the number of teeth on the ring gear.

Accordingly, torque balance relates to the state where a torque acts ona ring gear arranged in the planetary gear, representing the product ofthe torque acting on the planetary wheel carrier of the planetary gearand the gear ratio of the planetary gear, while simultaneously a torqueacts on the planetary gear's sun wheel, representing the product of thetorque acting on the planetary wheel carrier and (1 minus the planetarygear's gear ratio). At such torque balance said first locking means 34does not transfer any torque between the components of the planetarygear. Once torque balance has been achieved, the first locking means 34may easily be moved to the release position, so that the planetarygear's components are no longer locked together.

A great advantage of a drive system according to FIG. 3, with or withoutthe second locking means, which the present invention is focused on, isthe potential for continuous electric power supply by electric units inall operating modes with the combustion engine connected in a steadystate. This is normally not achieved with hybrid solutions having onlyone electrical machine. When the first locking means is in a lockedposition, said electric unit is supplied by substantially distributingthe requested electrical power to the electric auxiliary units and theelectric loads of the vehicle between the electrical machines. In thisway, the losses in the electrical machines are minimized since thetorque per electrical machine is halved compared to where an electricalmachine had supplied all the electrical power. Since the loss effects ofthe electrical machines substantially scale against the torque appliedsquared, this entails substantially a halving of the losses of theelectrical machines.

When the first locking means is open, the first electrical machine willdetermine the torque in the powertrain. The engine speed of thecombustion engine is controlled to an operational point, which isselected by minimizing the losses of the combustion engine together withlosses of the electrical machine and the inverter. The second electricalmachine is then used to balance the power for potential energy storagemeans, electrical units and the first electrical machine. It is a greatstrength that the power supply of the electrical units may take place,even if the vehicle is not equipped with an electrical energy storagesystem. The supply may also take place continuously during all types ofup- and down-shifts, during crawling, start-off and braking. All drivingmodes except electrical driving and brake regeneration, may be carriedout without any electrical storage means or with a defective energystorage means. In operating modes, with or without a defectiveelectrical energy storage, y the voltage of the second electricalmachine normally will be controlled to maintain the correct voltagelevel on the DC-link (supply voltage to the two inverters connected tothe stators of the electrical machines). It is also conceivable that thevoltage of the first electrical machine may be controlled in some cases.Voltage control is a “mode” of the inverter where a voltage is requestedfrom the inverter. The inverter then controls the electrical machine'storque so that the requested voltage is maintained on the inverter'ssupply side.

FIG. 4 shows, in a simplified way, a drive system which differs from theone according to FIG. 3, since the combustion engine 2 is permanentlyconnected with the second electrical machine's rotor 32. Embodiments ofthe inventive method may be carried out in vehicles with thesealternative drive systems.

FIG. 5 illustrates a flow chart of a method according to one embodimentof the present invention, implemented in a vehicle with a drive systemof the type displayed in FIGS. 3 and 4. At the performance of theinventive method for supplying electrical power to electrical auxiliaryunits and/or loads present in the vehicle, in a first method step S₁ thecombustion engine is kept running with its output shaft connected withthe second electrical machine's rotor. In a method step S₂ carried outin parallel, electrical auxiliary units and/or loads present in thevehicle are supplied with electrical power via the first and secondelectrical machines.

Computer program code for implementation of a method according to theinvention is suitably included in a computer program which is loadableinto the internal memory of a computer, such as the internal memory ofan electronic control device of a vehicle. Such a computer program issuitably provided via a computer program product, comprising a datastorage medium readable by an electronic control device, which datastorage medium has the computer program stored thereon. Said datastorage medium is e.g. an optical data storage medium in the form of aCD-ROM, a DVD, etc., a magnetic data storage medium in the form of ahard disk drive, a diskette, a cassette, etc., or a Flash memory or aROM, PROM, EPROM or EEPROM type memory.

FIG. 6 very schematically illustrates an electronic control unit 18comprising execution means 37, such as a central processor unit (CPU),for the execution of computer software. The execution means 37communicates with a memory 38, e.g. a RAM memory, via a data bus 39. Thecontrol device 18 also comprises a durable data storage medium 40, e.g.in the form of a Flash memory or a ROM, PROM, EPROM or EEPROM typememory. The execution means 37 communicates with the data storage means40 via the data bus 39. A computer program comprising computer programcode for the implementation of a method according to the invention isstored on the data storage medium 40.

The invention is obviously not limited in any way to the embodimentsdescribed above, but numerous possible modifications thereof should beobvious to a person skilled in the area, without such person departingfrom the spirit of the invention as defined by the appended claims.

The inventive method could be carried out in a vehicle with a drivesystem, which has the planetary gear's ring gear as said first componentand the sun wheel as said third component, which means that the firstelectrical machine's rotor would be connected with the planetary sunwheel and the second electrical machine's rotor and the combustionengine would be connected with the planetary gear's ring gear instead ofwith the sun wheel. Advantageously, however, the planetary gear's outputshaft for transmission of torque for the vehicle's propulsion isconnected with the planetary wheel carrier.

Nor is it necessary for the output shaft from the planetary gear to bean input shaft in a gearbox, instead the vehicle could have no gearbox.

1. A method for control of a vehicle with a drive system comprising anoutput shaft in a combustion engine, a first electrical machine,comprising a stator and a rotor, a planetary gear comprising threecomponents in the form of a sun wheel, a ring gear and a planetary wheelcarrier, wherein the combustion engine's output shaft is connected witha first of said components in the planetary gear, so that a rotation ofsuch shaft leads to a rotation of such first of said components, whereinan output shaft of the planetary gear is connected with a second of saidcomponents in the planetary gear, for transmission of torque for thevehicle's propulsion, so that a rotation of such shaft leads to arotation of said second of said components, and the electrical machine'srotor is connected with a third of said components in the planetarygear, so that a rotation of the rotor leads to a rotation of such thirdof said components, wherein the drive system also comprises a firstlocking means which may be moved between a locked position, in which twoof said components are locked together so that the three componentsrotate with the same rotational speed, and a release position in whichthe components are allowed to rotate at different rotational speeds,wherein the vehicle is controlled, whose drive system also comprises asecond electrical machine with a stator and a rotor connected with theoutput shaft of the combustion engine between the combustion engine andsaid first of said components and in that the method comprises thefollowing steps in order to supply electrical auxiliary units and/orloads present in the vehicle with electrical power: a) continuouslyrunning the combustion engine with its output shaft connected with thesecond electrical machine's rotor; and b) supplying said electricalauxiliary units and/or loads with electrical power via the firstelectrical machine and/or the second electrical machine.
 2. The methodaccording to claim 1, wherein the method is implemented with said firstlocking means in its locked position, and in supplying said electricalauxiliary units and/or loads with electrical power via the firstelectrical machine and/or the second electrical machine, said electricalauxiliary unit and/or loads are supplied with electrical power requestedthereby, and distributed between the first and the second electricalmachines in such proportions that the total power loss is minimized. 3.The method according to claim 1, characterised in wherein the method isimplemented with said first locking means in its locked position, and insupplying said electrical auxiliary units and/or loads with electricalpower via the first electrical machine and/or the second electricalmachine, said electrical auxiliary units and/or loads are supplied withelectrical power requested thereby, in substantially equal parts by thefirst and the second electrical machines.
 4. The method according toclaim 1, wherein the method is implemented with said first locking meansin its release position, and in that it also comprises the followingsteps: c) controlling the engine speed of the combustion engine to anoperational point, selected by minimizing combustion engine lossestogether with losses in the electrical machines and losses in inverters,comprised in the vehicle's electrical systems for conversion of directvoltage to alternating voltage and vice versa; d) controlling the secondelectrical machine for balancing of the electrical power transmitted tosaid electrical auxiliary unit and/or loads and the first electricalmachine; and e) controlling the first electrical machine to achieve,throughout the progress of the entire method, a requested torque fortransmission to said output shaft of the planetary gear, whereincontrolling the engine speed, controlling the second electrical machine,and controlling the first electrical machine are carried outsubstantially in parallel.
 5. The method according to claim 1, wherein avehicle is controlled, which has a drive system which also comprises asecond locking means, which may be moved between a locked position inwhich the combustion engine's output shaft is locked together with thesecond electrical machine's rotor and said first of said components, anda release position in which the combustion engine's output shaft isdisconnected from the second electrical machine's rotor, and said firstof said components is allowed to rotate independently of these, whichare controlled, and in that the second locking means is in a lockedposition when the method is performed.
 6. The method according to claim1, wherein a vehicle is controlled, whose drive system also comprises atleast one electric energy storage means for exchange of electrical powerwith the first and the second electrical machines and said electricalauxiliary units and/or loads.
 7. The method according to claim 1,wherein supply of said electrical auxiliary unit and/or loads withelectrical power is implemented in such a way that power balance isachieved, wherein free selection, within the limitations generallyspecified for the drive system, of charge current to, or dischargecurrent from electric energy storage devices, and/or electric auxiliaryunits and/or loads occurs that may be present in the vehicle, occurs inaccordance with the prevailing operational situation in the vehicle. 8.The method according to claim 7, wherein a maintenance of power balanceis temporarily waived where needed, when said supply is carried out. 9.The method according to claim 1, wherein the method is implemented outin the vehicle with a said drive system, in which the planetary gear'ssun wheel is said first of said components and its ring gear is saidthird of said components.
 10. The method according to claim 1, whereinthe method is carried out in a vehicle with a gearbox with an inputshaft, which is connected with said output shaft of the planetary gear.11. (canceled)
 12. A computer program product comprising computerprogram code for supplying electrical auxiliary units and/or loadspresent in a vehicle with electrical power, wherein the vehiclecomprises a drive system comprising an output shaft in a combustionengine, a first electrical machine, comprising a stator and a rotor, aplanetary gear comprising three components in the form of a sun wheel, aring gear and a planetary wheel carrier, wherein the combustion engine'soutput shaft is connected with a first of said components in theplanetary gear, so that a rotation of such shaft leads to a rotation ofsuch first of said components, wherein an output shaft of the planetarygear is connected with a second of said components in the planetarygear, for transmission of torque for the vehicle's propulsion, so that arotation of such shaft leads to a rotation of such second of saidcomponents, and the electrical machine's rotor is connected with a thirdof said components in the planetary gear, so that a rotation of therotor leads to a rotation of such third of said components, wherein thedrive system also comprises a first locking means which may be movedbetween a locked position, in which two of said components are lockedtogether so that the three components rotate with the same rotationalspeed, and a release position in which the components are allowed torotate at different rotational speeds, wherein the vehicle iscontrolled, whose drive system also comprises a second electricalmachine with a stator and a rotor connected with the output shaft of thecombustion engine between the combustion engine and said firstcomponent, wherein the computer program product is stored in anon-transitory computer-readable medium and comprises computer-readableprogram code portions embodied therein, the computer-readable programcode portions comprising computer code to cause an electronic processorto: a) continuously run the combustion engine with its output shaftconnected with the second electrical machine's rotor; and b) supply saidelectrical auxiliary units and/or loads with electrical power via thefirst electrical machine and/or the second electrical machine.
 13. Anelectronic control device for supplying electrical auxiliary unitsand/or loads present in a vehicle with electrical power, wherein thevehicle comprises a drive system comprising an output shaft in acombustion engine, a first electrical machine, comprising a stator and arotor, a planetary gear comprising three components in the form of a sunwheel, a ring gear and a planetary wheel carrier, wherein the combustionengine's output shaft is connected with a first of said components inthe planetary gear, so that a rotation of such shaft leads to a rotationof such first of said components, wherein an output shaft of theplanetary gear is connected with a second of said components in theplanetary gear, for transmission of torque for the vehicle's propulsion,so that a rotation of such shaft leads to a rotation of such second ofsaid components, and the electrical machine's rotor is connected with athird of said components in the planetary gear, so that a rotation ofthe rotor leads to a rotation of such third of said components, whereinthe drive system also comprises a first locking means which may be movedbetween a locked position, in which two of said components are lockedtogether so that the three components rotate with the same rotationalspeed, and a release position in which the components are allowed torotate at different rotational speeds, wherein the vehicle iscontrolled, whose drive system also comprises a second electricalmachine with a stator and a rotor connected with the output shaft of thecombustion engine between the combustion engine and said firstcomponent, wherein said electronic device comprises: a storage device;an electronic processor operatively coupled to the storage device; and acomputer program product stored in a non-transitory computer-readablemedium on the storage device and comprising computer-readable programcode portions embodied therein, the computer-readable program codeportions comprising computer code to cause an electronic processor to:a) continuously run the combustion engine with its output shaftconnected with the second electrical machine's rotor; and b) supply saidelectrical auxiliary units and/or loads with electrical power via thefirst electrical machine and/or the second electrical machine.